Energy-saving cooling systems for injection molding machines

Energy-saving cooling systems for high-performance injection molding machines are needed to reduce the energy consumption of powerful cooling systems. It is thanks to such installations that it is possible to substantially reduce the operating costs of cooling and improve the quality of production as a whole. Industrial processes require large volumes of cold water, the temperature of which must remain stable for a long time. In such cases, you can use free coolers (dry cooling towers).

Drycoolers or dry coolers are water-air heat exchangers that provide cooling of water through ambient air passing through the heat exchanger plates with the help of axial fans. At the same time, energy consumption is significantly lower compared to compressor coolers. Therefore, in those processes where possible, free coolers are used instead of compressor-based chillers, which leads to a reduction in running costs. 
Free-coolers have a huge cooling potential in the cold season, and therefore they are widely used in energy-efficient centralized cooling systems. 

Total energy saving
When the required water temperature is always above the ambient temperature, the free cooler can operate year-round, providing greater energy savings compared to water chillers. 

Partial energy savings
When the required water temperature is below ambient temperature (in summer), the freecooler must be used in conjunction with a water chiller. In this case, energy savings are possible only in cold weather, and depend on the geographical location and the required water temperature. 

Calculation of energy savings
An estimate of energy savings is possible when the annual values ​​of the ambient temperature (for a specific geographic area) and the number of hours of operation per year are known. Based on the specific temperature of the working water and working time during the year, it is possible to calculate the energy consumption, the comparative costs for the free cooler and the water chiller. 
These calculations provide a very reliable basis for evaluating the payback of equipment. 

Example No. 1 refers to the systems shown in Figures 1 and 3 below.
Cooling of one circuit is 
required . Required cooling capacity: 200 kW 
Water temperature: 15 ° C  
Region: Moscow region 
Average duty cycle of free cooler per circuit (cold): 67% time
Energy savings: 256 850 kWh or 65%. 

Example No. 2 refers to the system shown in Figure 2 below.
It is necessary to cool the two 
LTC circuits (low-temperature circuit) - the required cooling capacity of 80 kW at a water temperature of 15 ° C 
HTC (high- temperature loop) - required cooling capacity 120 kW at 33 ° C water temperature 
Region: Kiev region Freecooler 
cycle for HTC circuit - 100% of the time 
Energy saving: 300,000 kWh per year, or 76% 

As a result, the energy-saving cooling system pays off for a period of two to n years, depending on the specifics of production.
As a rule, any existing cooling system can be equipped with additional equipment to ensure the advantages of energy-saving systems. 

Cooling TPA single-circuit scheme 
The system has one circuit for cooling hydraulic drives and molds TPA. 
Applicable with water temperature limitations for hydraulics cooling 20-25 ° C

Figure 1.1	Figure 1.2
"Summer"  - normal operation:  Compressor cooler - on, cooling circuit  Dry cooler - off  Three-way valve - dry cooler is excluded from the circuit	"Winter"  - energy saving mode of operation:  Compressor cooler - pump on, compressors off  Dry cooler - on, circuit cooling  Three-way valve - dry cooler included in the circuit

Cooling TPA two-circuit scheme
The system has two circuits: for cooling hydraulic drives and cooling molds TPA. 
It is used with water temperature limitations for hydraulics cooling up to 35-40ºС.

Figure 2.1	Figure 2.2
"Summer"  - normal operation mode:  Compressor cooler: switched on cooling of the mold circuit  Dry cooler: switched on for cooling of the hydraulic circuit  Three-way valve: the circuits are separated	"Winter"  - energy-saving operation mode:  Compressor cooler: pump on, compressors off  Dry cooler: switched on for cooling of both circuits  Three-way valve: the circuits are combined

Cooling the baths of extrusion lines
The system has one circuit for cooling the distribution tank. 
The cooler does not have its own pump. One pump is installed at the outlet of the tank.

Figure 3.1.	Figure 3.2
"Summer"  - normal operation:  Compressor cooler - on, cooling circuit  Dry cooler - off  Three-way valve - dry cooler is excluded from the circuit	"Winter"  - energy saving mode of operation:  Compressor cooler - pump on, compressors off  Dry cooler - on, circuit cooling  Three-way valve - dry cooler included in the circuit